Optical record carrier containing special codes

ABSTRACT

A record carrier of a disc-like optically inscribable type, has a preformed track in which an auxiliary signal including a sequence of codes recorded by a preformed track modulation. The codes include a sequence of address codes specifying the addresses of the track portions in which the address codes are recorded and special codes. The special codes can be distinguished from the address codes and specify control data for controlling a recording by a recording device. The record carrier is provided with an extended area preceding a program calibration area. The extended area includes special codes representing additional control information for controlling the recording.

CROSS-REFERENCE TO RELATED APPLICATIONS

This is a continuation of U.S. Ser. No. 10/014,186, filed Dec. 11, 2001now U.S. Pat. No. 6,952,388, by Jakob Gerrit Nijboer, et al., andentitled, RECORD CARRIER OF THE OPTICAL TYPE AND A DEVICE FOR RECORDINGAND/OR PLAYBACK FOR USE WITH SUCH RECORD CARRIER.

FIELD OF THE INVENTION

The invention relates to a record carrier and a device for recording toand/or playback of the record carrier.

BACKGROUND OF THE INVENTION

Such a record carrier and device are known from the European Patent EP 0397 238. The special codes therein comprise special informationcontaining for instance control information for recording, such as writepower, location of special areas on the record carrier, a referencerecording speed, disc application codes, disc type and so on. This hasbeen applied in products commonly known under the name of recordableCompact Disc or CD-R. In practice the amount of information to be storedin the special codes proves to be limited. To solve this, the definitionof the special codes could be changed in order to be able to increasethe capacity of information to be stored therein. However, this willresult in incompatibility with existing systems and standards present onthe market.

OBJECT AND SUMMARY OF THE INVENTION

In consequence, amongst other things, it is an object of the inventionto increase the amount of control information to be stored in thespecial codes without changing the definition of the special codes.According to one of aspects, a record carrier includes an extended area(XAA).

This extended area (XAA) may be used to record additional controlinformation in the special codes (SC). By locating this extended areaoutside the known areas, legacy recording devices already present in themarket will not be distracted by this extended area, as this extendedarea (XAA) is outside usual regions for such devices. However, only newrecording devices, with for example increased recording speedcapabilities, may be adapted to handle the control information recordedin the extended area. By locating this extended area adjacent theprogram calibration area (PCA) a recording device will have no majordifficulties to move its reading means above this extended area.Further, as normally a recording device will start looking for controlinformation in the lead-in area (LI), a subsequent jump to the extendedarea (XAA) will not require large access times.

An advantageous embodiment is obtained by having a buffer area locatedbetween the extended information area (XAA) and the program calibrationarea (PCA) containing only address codes (AC). The buffer area that mayprotect existing drives against slipping into an area with contents thatthey do not know.

A preferred embodiment is obtained by having a buffer area that covers arange of absolute playback time (ATIP) of between 1 and 2 seconds. Thebuffer area should be as small as possible in order to keep the endradius of the extended area (XAA) as large as possible.

A next embodiment is obtained by having the extended information area(XAA) precedes the start of the lead-in area (LI) by approximately 1minute absolute playback time (ATIP). This limits the inner displacementof reading means of a recording device to such an extent that thedisplacement falls in a mechanical allowed range.

A further advantageous embodiment is obtained by having a periodicpattern of address codes and special codes where the pattern in thelead-in area (LI) has a predetermined positional relationship withrespect to a predetermined reference address. Such a predeterminedpositional relationship can be used to indicate the presence of theextended area (XAA). A recording device adapted to handle information ofthe extended area, will then, after starting with reading theinformation in lead-in area, continue reading in the extended area.

An advantageous embodiment of a record carrier is obtained by having thepredetermined reference address be the start address or end address ofthe lead-in area (LI). The start address or end address may be specifiedin the special information which can be read in advance. This provides aunique reference for each disc witch can be used to define a positionalrelationship.

A further advantageous embodiment of a record carrier is obtained byshifting periodic pattern is by a predetermined number of address codes(AC) with respect to the predetermined reference address. Such a shiftis relatively easy to establish by comparing address codes.

A device for recording and/or playback according to the inventionobtained by a device that is able to detect the presence of a recordcarrier provided with such additional control information andconsequently using this information.

A further advantageous embodiment is obtained by shifting the periodicpattern by a predetermined number of address codes (AC) with respect tothe predetermined reference address. Only in case the predeterminedpositional relationship is being detected, a jump of appropriate readingmeans across the record carrier is being performed. The device does needto perform such a time consuming jump if there is no need for, such asfor instance in case of a record carrier without the additionalinformation. Then there will be no performance loss in case of handlingsuch discs.

BRIEF DESCRIPTION OF THE DRAWINGS

These and further aspects and advantages of the invention will bediscussed in more detail hereinafter with reference to the disclosure ofpreferred embodiments, and in particular with reference to the appendedFigures that show:

FIG. 1 a record carrier provided with a servo-track which exhibits atrack modulation;

FIG. 2 illustrates a suitable format for an auxiliary signal which isrecorded in the servo track by means of track modulation;

FIG. 3 gives a code word represented by the auxiliary signal;

FIG. 4 shows the lay-out of a record carrier;

FIG. 5 gives a number of bit combinations used in the auxiliary codesand address codes;

FIG. 6 shows a possible sequence of successive address codes and specialcodes in the Lead-in area of a record carrier;

FIG. 7 shows a sequence according to a first embodiment of the inventioncomprising a shift with respect to the start of the Lead-in area;

FIG. 8 shows a sequence according to a second embodiment of theinvention comprising a specific order of the special codes;

FIG. 9 shows a sequence according to a third embodiment of the inventioncomprising a shift with respect to start of the Lead-in area;

FIG. 10 shows an embodiment of a recording and/or playback deviceaccording to the invention;

FIG. 11 shows a flow chart of a control program for controlling theprocess of recording information;

FIG. 12 shows a fourth embodiment of the invention comprising allocationof the additional control information in an extended area of the Lead-inarea:

FIG. 13 shows a fifth embodiment of the invention comprising allocationof the additional control information mixed in the Lead-in area.

DESCRIPTION OF THE EMBODIMENTS

FIG. 1 shows possible embodiments of a record carrier 1 of aninscribable type as described, for example, in the European Patent EP 0325 330 (PHN 12.399). FIG. 1 a is a plan view. FIG. 1 b shows a smallpart of a sectional view taken on the line b-b. FIGS. 1 c and 1 d arehighly enlarged plan views of a part 2 of a first embodiment and asecond embodiment of the record carrier 1. The record carrier 1 has atrack 4, constituted for example by a preformed groove or ridge. Thetrack 4 is intended for recording an information signal. For the purposeof recording the record carrier 1 has been provided with a recordinglayer 6 deposited on a transparent substrate 5 and coated with aprotective layer 7. The recording layer 6 is of a material which, whenexposed to suitable radiation of adequate intensity, is subjected to anoptically detectable change. Such a layer may be, for example, a thinlayer of a metal such as tellurium. By exposure to laser radiation ofsuitable intensity this metal layer can be melted locally, so that atthis location said layer will have a different reflection coefficient.When the track 4 is scanned by a radiation beam whose intensity ismodulated in conformity with the information to be recorded aninformation pattern of optically detectable recording marks is obtained,which pattern is representative of the information.

The layer may alternatively consist of other radiation—sensitivematerials, for example magneto-optic materials, a dye, or materialswhich upon heating are subjected to a structural change, for examplefrom amorphous to crystalline or vice versa. A survey of such materialsis given in the book “Principles of optical disc systems”, Adam HilgarLtd., Bristol and Boston, pp. 210-227.

The track 4 enables a radiation beam which is aimed at the recordcarrier 1 for the purpose of recording the information to be positionedaccurately on the track 4, in other words it enables the position of theradiation beam in a radial direction to be controlled via a trackingsystem employing the radiation reflected from the record carrier 1. Themeasurement system for measuring the radial position of the radiationspot on the record carrier may correspond to one of the systems asdescribed in the above mentioned book “Principles of optical discsystems”.

The auxiliary signal is recorded in the track 4 by means of a preformedtrack modulation, suitably in the form of a sinusoidal track excursionas shown in FIG. 1 c. However, other track modulations such as forexample track width modulation (FIG. 1 d) are also suitable. Since atrack excursion is very easy to realise in the manufacture of the recordcarrier it is preferred to use a track modulation in the form of such atrack excursion.

It is to be noted that FIG. 1 shows the track modulation to a highlyexaggerated scale. In reality it is found that in the case of a trackwidth of approximately 10⁻⁶ meters an excursion having an amplitude ofapproximately 30.10⁻⁹ meters is adequate for a reliable detection of thescanning beam modulation. An excursion of small amplitude has theadvantage that the distance between adjacent servo tracks can be small.FIG. 1 also shows the track pitch (the spacing between the trackcentres) to a substantially larger scale than in reality. In practicethe track pitch is approximately 1.6 10⁻⁶ meters.

An attractive track modulation is that in which the frequency of thetrack modulation is modulated in conformity with the auxiliary signal.However, other track modulations are also possible.

FIG. 2 gives an example of a suitable auxiliary signal comprising codesignals 12 which alternate with synchronising signals 11. Each codesignal 12 may comprise a “biphase-mark” modulated signal having a lengthof 76 channel bits, which signal is representative of a code wordcomprising 38 code bits. In the case of a “biphase-mark” modulatedsignal each code bit is represented by two successive channel bits. Acode bit of a first logic value, in the present example “0”, isrepresented by two bits of the same logic value. The other logic value(“1”) is represented by two channel bits of different logic values.Moreover, the logic value of the “biphase-mark” modulated signal changesafter every pair of channel bits (see FIG. 2), so that the maximumnumber of successive bits of the same logic value is two at the most.The synchronising signals 11 are selected in such a way that they can bedistinguished from the code signals 12. This is achieved when themaximum number of successive bits of the same logic value in thesynchronising signals 11 is selected to be three.

FIG. 3 shows a suitable format of 38-bit code words 17 represented bythe code signals 12. The code word 17 shown therein comprises threebytes 13, 14 and 15 of 8 bits each and a 14 bit group 16. The mostsignificant bits of the bytes 13, 14 and 15 bear the reference numerals20, 21 and 22 respectively. The bytes 13, 14 and 15 are used asinformation bytes and the 14 bit group 16 comprises parity bits for thepurpose of error detection. The values represented by the bytes 13, 14and 15 are referenced mm, ss and ff respectively. Preferably, the 38-bitcode words are recorded in the track at equidistant positions andcomprise address codes AC and special codes SC which can bedistinguished from each other and which are recorded in the track, forexample in the sequence illustrated in FIG. 6.

In FIG. 6 a constant number, in the present case 9, of address codes ACis always followed by an special code SC. However, it is to be notedthat the number of address codes AC between the special codes SC mayalso be variable instead of constant. The address codes may comprise forexample a time code, indicating the time required, when the track 4 isscanned at the nominal scanning speed, to bridge the distance between areference position in the track and the location where the address codeis recorded. Preferably the selected address code is a time codeidentical to the absolute time code as included in the subcode Q-channelduring recording of a CD signal. In that case the value mm specifies anumber of minutes and the values ss and ff denote a number of secondsand a number of frames respectively, the specified number of secondsvarying between 0 and 59 and the specified number of frames varyingbetween 0 and 74. The number of minutes, seconds and frames may forexample BCD encoded in the bytes 13, 14 and 15.

The advantage of the address code described above becomes apparent inparticular in the case that a CD signal is to be recorded on the recordcarrier. In that case the absolute time code to be included in thesubcode Q-channel can be derived directly from the address code beingread, as is described in detail in the European Patent EP 0 325 330 (PHN12.399).

When a standard CD signal is recorded three different areas can bedistinguished on the record carrier, as is illustrated in FIG. 4,namely:

-   1) a program area situated between the radial positions bounded by    the radii r2 and r3. In this area the data signals are recorded;-   2) a Lead-in area situated between the radial positions bounded by    the radii r1 and r2. This area comprises a Lead-in track in which    the addresses of the different data signals in the program area are    stored in the form of a table of contents, as is described, for    example, in Nederlands Patent Application NL-A-8900766 (PHN 12.887).-   3) a Lead-out area situated between the radial positions bounded by    the radii r3 and r4. This area comprises a lead-out track in which a    lead-out signal which can be distinguished from the data signals is    recorded to mark the end of the program area.

The radial positions of the beginning of the Lead-in area and thebeginning of the program area are prescribed by the CD standard, therequired distance from the beginning of the lead in area to the centreof rotation r0 being 23 mm, while the distance from the beginning of theprogram area to the centre of rotation r0 should be 25 mm. Moreover, thelead-out area is required to begin before a predetermined radialposition.

For an optimum use of the address code recorded by means of the trackmodulation it is desirable that the values of the address codes recordedin the track vary identically to the absolute time code in the CD signalto be recorded. This means that the value of the address code in thetrack portion whose the radial position is indicated by r2 is 00:00:00.Preferably the value of the address code in the Lead-in area increasesto a value 99:59:74 at the end of this area. This has the advantage thatthe value 00:00:00 of the first address code in the program areadirectly follows the value 99:59:74 of the last address code in thelead-in area.

As already stated, it should be possible for the special codes and theaddress codes to be distinguished from one another. This can beachieved, for example, if the code signals representing the addresscodes and the code signals representing the special codes are precededby different synchronisating signals 11. A number of differentsynchronisation signals 11 which may be used in conjunction with thecode signals 12 described herein are described inter alia in theEuropean Patent No EP 0 342 748 (PHN 12.571).

However, the special codes can also be distinguished from the addresscodes if the special code contains specific bit combinations in which donot occur in the address code. If the time codes described above areused for the address codes, this is possible by means of a bitcombination comprising the most significant bits 20, 21 and 22 for thethree bytes 12, 14 and 15, which will be explained with reference toFIG. 5.

In FIG. 5 the reference numeral 66 denotes the possible bit combinationof the address codes in the Lead-in area. On account of the high valuemm of the byte 13 in the Lead-in area the most significant bit 20 of thebyte 13 in this area will always have the logic value 1. The value ss ofthe byte 14 varies between 0 and 59, which in the case of the BCDencoding means that the most significant bit 21 of the byte 14 alwayshas the logic value 0. The value ff of the byte 15 varies between 0 and74, so that the most significant bit 22 for the byte 15 also always hasthe logic value 0. The other bits of the bytes 13, 14 and 15 in the bitcombination 66 may assume either the logic value 0 or the logic value 1,which is indicated by the symbol “x”.

The reference numeral 67 denotes the possible bit combinations of thebytes 13, 14 and 15 of the address code in the track portion situatedoutside the Lead-in area. For the same reasons as in the case of theaddress code in the lead in area the most significant bits 21 and 22 ofthe bytes 14 and 15 in the bit combination 67 always have the logicvalue 0. Moreover, on account of the limited playing time of the recordcarriers address codes having a value for which the most significant bit20 in the bit combination 67 assumes the value 1 do not occur in theprogram area.

The reference numerals 61, 62, 63, 64, 65 and 69 represent a number ofbit combinations for which the combination of the most significant bits20, 21 and 22 of the bytes 13, 14 and 15 differ from the correspondingbit combinations in the address codes. Therefore the bit combinationsmay be used for the special codes SC, in which case the seven leastsignificant bits of the bytes 13, 14 and 15 can represent additionalinformation. For example the bit combinations 61 can be employed torepresent the address code of the Lead-out area. Since the mostsignificant bits of the bytes 13, 14 and 15 of the address codes for theLead-out area always assume the same logic 0 value, the value of theaddress code for the Lead-out area may be represented completely by theseven least significant bits of the bytes 13, 14 and 15 in the bitcombination 61.

Similarly, the value of the address code for the Lead-in area may berepresented by the bit combination 62. The bit combinations 63, 64 and65 can be employed for special codes with which other additionalinformation is recorded in the track, such as for example the writeenergy required for recording, the type of record carrier, the writestrategy etc.

As can be seen from the definition of a special code as disclosed inFIG. 5, a limited number of bits are available for special information.As such a special code may in practice being incorporated in a standard,there is no possibility of storing a larger number bytes, as this wouldeffect compatibility with legacy player/recorders. To deal with thisproblem, it is possible to use another area of the disc, for instancethe Lead-out area. However, it is not advantageous having drives inplayer/recorders to jump to this area if there is no information there,in case of a legacy disc, because of the time this takes. Therefore, theembodiments according to the invention, solve this problem by indicatingin the special codes, without effecting compatibility, either suchinformation or the presence of such information in another area of thedisc.

In practice, the start time of the Lead-in area is indicated in such aspecial code, according to existing standards. The frame of the Lead-inarea will be referred to hereinafter to as SLI. A drive can, whenstarting up, jump somewhere in the Lead-in area and start reading untilit recognises special codes. In practice, the discs will start with aspecial code SC at SLI, a next special code SC at SLI+10 and so on.However, as current standards prescribe such special code must be usedcyclic and must be successively be repeated, the start of such asequence is not being prescribed.

To put more information of the disc, for instance to indicateavailability of special codes in the Lead-out area, the position of thespecial codes if shifted for n frames, as illustrated in FIG. 7 showinga first embodiment according to the invention of possible address codesand special codes.

The shift of n frames of a pattern P of one special code SC and nineaddress codes AC, is defined with respect to the start SLI of theLead-in area. A drive according to the invention, can calculate n bylooking at the differences (in frames) of the found addresses of thespecial codes SC and the start address SLI of the Lead-in area, the lastone being specified in the special codes. Either the amount of such ashift n may indicate additional information to be used by a drive ascontrol information or the the shift may refer to existence of suchinformation elsewhere. This additional information may compriseinformation with respect to the write strategy of the disc. This maybecome relevant of high speed discs which require sophisticatedapproaches to write, the definition of such approaches not beingforeseen when defined the format of the special codes.

Even when an existing disc has such a shift n, a drive according to theinvention may jump and lose some time, but the system will not fail.There is only a performance problem in such a case. Legacy drives willnot be tempered by the shift n. So this legacy drives can write newdiscs, according to the invention, the old way, due to backwardscompatibility of the old disc and old discs can be written on newdrives, according to the invention, without delay due to the fact thatn=0.

It is noted that instead of defining a shift with respect to the startSLI of the Lead-in area, this may alternatively be done with respect tothe end of the Lead-in area or even with respect to the start of theLead-out area. The shift may thus also being defined backwards.

An second embodiment according to the invention is shown in FIG. 8,where a pattern P comprises an ordered sequence of respectively threedistinct special codes SC1, SC3, and SC2. These distinct special codesbeing individually identifiable, as disclosed with reference to FIG. 5,by bits 20, 21 an 22. As the specific order in a pattern P as such isnot being prescribed by the current standards, this order can be used toencode additional information or the presence thereof.

A third embodiment according to the invention is shown in FIG. 9,disclosing a pattern P of special codes SC1, SC2 and SC3 and addresscodes AC, the pattern being shifted with n frames. The special codeswithin in a pattern P may have, or may not have a prescribed order.

As noted before, the additional control information may be stored in theLead-out area. However, further advantageous embodiments of theinvention are obtained by storing the additional control information ineither an extended area of the Lead-in area or either mixed in theLead-in area. These embodiments having the advantage of not needing tojump to the Lead-out area, which jump increases access time. It is notedthat storing additional control information in the Lead-in area in theindicated manner may be indicated by including a phase jump or a specialorder as disclosed before. However, such an indication of the presenceof such information may also be omitted as the disadavantage of a jumpto a Lead-in area is not present in these embodiments.

FIG. 12 shows a fourth embodiment according to the invention, comprisingstoring the additional control information in an extended area near theLead-in area. This will be referrred to as an extended ATIP area. Toavoid compatibility problems with existing lower speed drives, any ofthe existing areas should be avoided. This also applies to the bufferarea in the Program Calibration Area (PCA), which are needed for access.The idea is to extend the grooved area towards the inside of the disc,and fill this additional area with Special Info and Additional Info,except for an additional buffer with timecode only. This buffer area hasto protect existing drives against slipping into an area with contentsthat they do not know, however the buffer shall be as small as possible,to keep the end radius of the eXtended Info Area (XIA) as large aspossible. The advantage being that that there is no backwardscompatibility as the Extended ATIP Area (XAA) is outside usual regionsfor “old” players. Further the “old” players will treat the discsaccording to the invention as the “old” discs. A further advantage ofthis embodiment is the very fast ATIP Info access for “new” players.Because of ATIP Info “phase offset” in Lead-in Area, a player can detecta disc according to the invention within 10 frames (average 5) and jumpto XAA to read full ATIP Info (only 8 frames). These and other detailsof this embodiment are shown in FIG. 12.

A fifth embodiment will be disclosed with reference to FIG. 13. Theadditional control information in this embodiment is mixed in theLead-in area. It is assumed that most players will start reading ATIPinfo in the second ‘half’ of the Lead-in area. In this case the Lead-inarea is part 1 is to act as a protection buffer for access of the PMAArea, part 2 is to store all Special Info and Additional Info, and part3 is to be the “compatibility” part of the Lead-in Area. The advantageof the fifth embodiment being that there are no mechanical limitationsfor the “new” players according to the invention.

Although it is noted that the invention is described with reference tothe current standards for CD-recordable or CD-R, this may also beapplied to systems with information in a wobble signal, such asCD-rewritable or CD-RW and DVD.

FIG. 10 shows an embodiment of a recording device for recording datasignals Vi on the record carrier 1 described above. The record carrier 1is placed on a turntable 80, which is rotated by means of a motor 81. Anoptical write/read head 82 of a customary type is arranged opposite thecarrier 1 to read and/or record information from/in the track 4 by meansof a radiation beam 83 which is aimed at the recording layer 6. The readhead 82 is movable in a radial direction relative to the record carrier1 by means of a system which comprises, for example, a motor 85 and aspindle 84. The beam 83 is focused on the recording layer 6 in acustomary manner and is kept on the track 4 with the aid of customaryfocusing and tracking systems, not shown. As the track is scanned thebeam is modulated in conformity with the preformed track modulation. Inthe read head 82 the beam which is thus modulated is detected by meansof customary radiation-sensitive detectors, which generate signalcurrents from which a detection signal Vd is derived by means of adetection circuit in a manner as described, for example, in the EuropeanPatent EP 0 265 984 (PHN 12.063), frequency of said detection signalcorresponding to the frequency of the track modulation. The detectionsignal Vd is applied to a motor control circuit 87 to control the speedof the motor in such a way that the frequency of the detection signal Vdremains equal to the frequency of a reference clock signal Ck. The motorcontrol circuit 87 may comprise, for example, a phase detector fordetecting the phase difference between the detection signal Vd and thereference clock signal Ck, and a power supply circuit for powering themotor with a voltage whose value depends on the phase difference thusdetected.

The detection signal Vd is also applied to an FM demodulator 88 torecover the auxiliary signal Vh from the detection signal Vd. Therecovered auxiliary signal Vh is applied to a synchronising-signaldetection circuit 89 for detecting the synchronising signals 11 in theauxiliary signal Vh and a “biphase-mark” demodulator 90 for convertingthe auxiliary signals into the 38-bit code words 17. The bits of the38-bit code words 17 are serially applied to an error-detection circuit91, which by means of the parity bits of the bit group 16 determineswhether the code word is received without errors. Moreover, the seriallysupplied code words 17 are applied to serial-parallel converter 92, onwhose output the bits of the bytes 13, 14 and 15 are available inparallel form. The most significant bits 20, 21 and 22 of the 3 bytes13, 14 and 15 applied to the outputs of the converter 92 are fed to acustomary decoder circuit 93, which generates eight signals V1, V2, V3,V4, V5, V6, V7, V8, the relationship between the signals V1, . . . V8and the most significant bits 20, 21 and 22 of the bytes 13, 14 and 15being given in the following Table 1.

TABLE 1 MSB 20 21 22 V1 1 0 0 V2 0 0 0 V3 0 1 0 V4 1 1 0 V5 0 0 1 V6 0 11 V7 1 1 1 V8 1 0 1The signals V3, V4, V5, V6, V7 and V8 are applied to a control circuit94 for controlling the recording device. The control circuit 94 maycomprise a microcomputer of a customary type, which is loaded withsuitable control program to be described hereinafter. The signals V1 andV2 on the output of the decoder circuit 93 are applied to a two-input ORgate 95. The signals V1 and V2 indicate that the bytes 13, 14 and 15 onthe output of the converter 92 represent an address code within theLead-in area or an address code outside the Lead-in area, so that theoutput signal of the OR gate 95 always indicates whether the outputsignal of the converter 92 concerns address information. The outputsignal of the OR gate 95 is applied to an input of the two-input ANDgate 96. A signal from the error-detection circuit 90, which signal eachtime indicates by means of a pulse that the received code word 17 iscorrect, is applied to the other input of the AND gate 96.

Thus, by means of a pulse the AND gate 96 each time indicates whetherthe information on the output of the converter represents a correctlyread address code. The output signal of the AND gate 96 is applied to aparallel load-enable input of a counting circuit 97. The bytes 13, 14and 15 appearing on the outputs of the converter 92 are applied to theparallel inputs of the counting circuit 97, so that upon every receiptof a correctly read address code the counting circuit 97 is loaded withthe address code being read. The counting circuit 97 is of a type whichin response to a clock pulse on a clock input of the counter incrementsthe count of the counter by one. A clock signal which is in synchronismwith the synchronisation signals 11 being read is applied to said clockinput, which clock signal is derived from an output signal of thesynchronising signal detection circuit 89 by means of a customary phaselocked loop circuit 103.

The counting circuit 97 operates as follows. In response to the clocksignal pulses supplied by the phase locked loop circuit 103 the count iseach time incremented by one in synchronism with the operation ofreading the code values recorded in the track. This means that as soonas the count has a value corresponding to the address codes being readthe value of the count will follow the values of the address code beingread regardless of whether the subsequent address codes are readincorrectly or the next code word 17 being read does not contain anaddress code AC but a special code code SC. If at the beginning thecount does not correspond to the address code being read the counter isresponsive to the next pulse on the output of the AND gate 96 to beloaded with the correct value supplied by the converter 92 via itsparallel inputs.

As long as the count correspond to the address code being read thepulses on the output of the AND gate will have no effect because thecount then already corresponds to the address code applied to theparallel inputs of the counting circuit. This method of deriving theaddress codes have the advantage that always an address codecorresponding to the position of the track being scanned is available,even in the case that instead of an address code AC an special code SCis recorded in the track. This also means that the track portions inwhich the address codes are recorded remain addressable. The bytes 13,14 and 15 on the output of the converter 92 are applied not only to theparallel inputs of the counting circuit 97 but also to the controlcircuit 94.

The control circuit will use the information in the special codes tocontrol the recording or reading process. Thereto, the control circuit94 is coupled to the write/read head 82 and the motor 85 via signallines 98 and 99. The read head can be set to a read mode or a write modevia the signal line 98. In the read mode the intensity of the radiationbeam 83 remains at a constant small value, which is too small to bringabout the optically detectable change in the recording layer 6. In thewrite mode the intensity of the radiation beam is switched in accordancewith a write signal Vs between a lower intensity level, which does notbring about an optically detectable change, and a high intensity level(also referred to as write energy), which gives rise to an opticallydetectable change in the recording layer 6, so that an opticallydetectable pattern corresponding to the write signal Vs is formed in therecording layer 6.

The special code may indicate itself information with respect to thiswrite signal Vs such as nominal writing power, such as customary withcurrent standards. However, additional information with respect to moresophisticated write strategies may be encoded in a manner as describedbefore according to the invention. The control circuit according to theinvention may comprise there to circuitry in hardware to detect a shiftin the pattern of special codes, the amount of shift and/or the order ofspecial codes within a pattern of address codes and special codes. Thismay alternatively done by a suitable program loaded in a memory andexecuted by a processor.

The write signal Vs is generated by an EFM modulation circuit 100, whichconverts a data signal Vi and the subcode information applied via a bus101 into an EFM modulated signal in conformity with the CD standard,from which the write signal Vs is derived in a manner as described indetail in, for example, Netherlands Patent Application NL-A-8700934 (PHQ87.009). Moreover, the high write level (write energy) can be set to avalue indicated in the special code.

The process of recording information on the record carrier is controlledby the control circuit 94, which for this purpose is loaded with asuitable control program. Such a control program may comprise, forexample the steps indicated in the flow chart in FIG. 11.

Step S1 is performed immediately after the record carrier 1 has beenloaded into the recording device. In this step S1 the read/write head 82is set to the read mode and by means of the signals V3 and V4 on theoutput of the decoder circuit 96 it is ascertained whether the code wordsupplied to the output of the converter 92 comprises a special codecontaining the address values of the Lead-in or the Lead-out area. Whenthe presence of theses special codes is detected the values of theLead-in area and of the Lead-out area are stored in a memory of thecontrol circuit. 94

Subsequently, in step S2, the read/write head 82 is directed towards thetrack portion containing the address code of the Lead-in area with theaid of the address code being read. Then the presence and content ofspecial codes is being read and stored in the control circuit 94. If notspecial shift and/or order of special codes within the pattern P ofaddress codes and special codes is being detected, writing continues asdescribed with reference to step S3, using control information presentedby the special codes. However, if such a special shift and/or order isbeing detected, the control circuit 94 may either use this informationfor controlling purpose of may direct the read/write head 82 to apredetermined location, such as for instance the Lead-out area forreading additional special codes containing additional controlinformation,

In step S3 the read/write head 82 is directed towards a track portion bymeans of the address codes being read. When this track portion isreached the read/write head 82 is set to the write mode, after which thedata signal Vi applied to the EFM modulation circuit 100 can berecorded. Recording is terminated once the complete data signal to berecorded has been recorded. Upon termination of the recording processstep S4 is performed, in which it is ascertained whether recording hasbeen discontinued as a result of the track portion specified by thestart address of the Lead-out being reached. If this is the case, stepS5 is performed, in which the lead-out signal is recorded during apredetermined time interval, the subcode information characterizing thelead-out signal being applied to the EFM modulation circuit by thecontrol circuit 94. After recording of the lead-out signal thewrite/read head 82 is directed towards the lead-in area in step S6 torecord the definitive table of contents in the lead-in area.

If during step S4 it is ascertained that recording of the data signalhas not been discontinued as a result of the track portion having theaddress code with the value AVO being reached, the provisional table ofcontents is recorded in the lead-in area during step 57. Subsequently,it is checked in step S8 whether further data signals are to be recordedon the record carrier. If this is the case the program is terminated. Ifthis is not the case, the definitive table of contents is recorded inthe lead-in area in step S9 and the lead out signal is recorded in stepS10, after which the program is terminated.

In the foregoing the invention has been illustrated for an opticalrecording system for recording a standard CD signal on a record carriercomprising substantially concentric tracks. However, it is to be notedthat the invention equally applies to the recording of signals in lineartracks. Moreover, the invention may also be applied to the recording ofother data signals than CD signals. Neither is the scope of theinvention limited to optical recording systems. It may equally beapplied to magneto-optical recording systems or magnetic recordingsystems where address codes have been recorded in the track by means ofa previously applied track modulation.

Finally it is remarked that although he invention has been describedwith reference to preferred embodiments thereof, it is to be understoodthat these are not limitative examples. Thus, various modificationsthereof may become apparent to those skilled in the art, withoutdeparting from the scope of the invention, as defined by the claims. Forinstance a CD-RW may be replaced with a DVD-RW or the like.

The invention may be implemented by means of both hardware and software,and that several “means” may be represented by the same item ofhardware. Further, the invention lies in each and every novel feature orcombination of features. It is also remarked that the word “comprising”does not exclude the presence of other elements or steps than thoselisted in a claim. Any reference signs do not limit the scope of theclaims.

1. A record carrier of the disc-like optically inscribable type, havinga preformed track in which an auxiliary signal comprising a sequence ofcodes is formed by a preformed track modulation, wherein the sequence ofcodes comprises a sequence of address codes specifying addresses oftrack portions in which said address codes are recorded and a pluralityof special codes for specifying control data for controlling a recordingby a recording device, wherein the preformed track consecutively from aninner part of the record carrier comprises: program calibration areareserved for recorder calibrating purposes; a program memory area fortemporarily storing recorded user content data; a lead-in area forstoring definitive recorded user content data; a program area forrecording user data; a lead-out area for indicating end of the programarea; wherein said special codes are recorded in the lead-in area and/orthe lead-out area; and an extended area preceding the programcalibration area containing special codes representing additionalcontrol information that are capable of controlling the recordingdevice; wherein the special codes contain bit combinations which do notoccur in the address codes and are indicative of commands forcontrolling the recording device.
 2. The record carrier of claim 1,wherein the extended area comprises an extended information areacomprising the additional control information and a buffer area locatedbetween the extended information area and the program calibration areacontaining only address codes.
 3. The record carrier of claim 2, whereinthe address codes are represented by an absolute playback time relativeto the start of the lead-in area, characterized in that, the buffer areacovers a range of absolute playback time of between 1 and 2 seconds. 4.The record carrier of claim 2, wherein the address codes are representedby an absolute playback time relative to the start of the lead-in area,characterized in that, the extended information area precedes the startof the lead-in area by approximately 1 minute absolute playback time. 5.The record carrier of claim 1, wherein the sequence of address codes andspecial codes comprise a periodic pattern of address codes and specialcodes such that the pattern in the lead-in area has a predeterminedpositional relationship with respect to a predetermined referenceaddress.
 6. The record carrier according to claim 5, wherein thepredetermined reference address is the start address or end address ofthe lead-in area.
 7. A device for recording to and/or playback of arecord carrier of the inscribable type as claimed in claim 5 comprising:a reading mechanism configured to read information recorded on therecord carrier, and a recording mechanism configured to record on therecord carrier in accordance with a recording process, the readingmechanism comprising means to read the auxiliary signal recorded on therecord carrier, selecting means for extracting the special codes and theaddress codes from the auxiliary signal, a control device that isconfigured to control recording and adapted to determine thepredetermined positional relationship of the periodic pattern of addresscodes and special codes and to read the extended area on the recordcarries upon detecting the predetermined positional relationship.
 8. Arecord carrier of the disc-like optically inscribable type, having apreformed track in which an auxiliary signal comprising a sequence ofcodes is formed by a preformed track modulation, which codes comprise asequence of address codes specifying the addresses of the track portionsin which said address codes are recorded and special codes forspecifying control data for controlling a recording by a recordingdevice, comprising: the preformed track comprises consecutively from aninner part of the record carrier; a program calibration area reservedfor recorder calibrating purposes, a program memory area for temporarilystoring recorded user content data, a lead-in area for storingdefinitive recorded user content data, a program area for recording userdata, and a lead-out area for indicating end of the program area; and anextended area preceding the program calibration area containing specialcodes representing additional control information that are capable ofcontrolling a player/recorder device; wherein the special codes containbit combinations which do not occur in the address codes and areindicative of commands for controlling the recording device.
 9. Therecord carrier of claim 8 wherein the extended area further comprises anextended information area comprising the additional control information;and a buffer area located between the extended information area and theprogram calibration area continuing only address codes.
 10. The recordcarrier of claim 9, wherein the address codes are represented by anabsolute playback time relative to the start of the lead-in area,characterized in that, the buffer area covers a range of absoluteplayback time.
 11. The record carrier according to claim 9, wherein theaddress codes are represented by an absolute playback time relative tothe start of the lead-in area, characterized in that, the extendedinformation area precedes the start of the lead-in area by apredetermined amount of time that controls displacement of the recordingdevice.
 12. The record carrier according to claim 8, wherein thesequence of address codes and special codes comprise a periodic patternof address codes and special codes within the lead-in area that has apredetermined positional relationship with respect to a predeterminedreference address.
 13. The record carrier according to claim 12, whereinthe periodic pattern comprising special codes separated by a firstnumber of successive address codes such that the periodic pattern isshifted by a predetermined number of address codes with respect to thepredetermined reference address.
 14. A device for recording to and/orplayback of a record carrier of the inscribable type as claimed in claim12, the device comprising: reading means for the reading the informationrecorded on the record carrier, and recording means for recording therecord carrier in accordance with a recording process, the reading meanscomprising means to read the auxiliary signal recorded on the recordcarrier, selecting means for extracting the special codes and theaddress codes from the auxiliary signal, control means for controllingthe recording process, characterized in that, the control means areadapted to determine the predetermined positional relationship of theperiodic pattern of address codes and special codes and to read theextended area on the record carrier upon detecting the predeterminedpositional relationship.
 15. Device according to claim 14, characterizedin that, the control means are adapted to initially read the specialinformation in the lead-in area and, only upon detection of thepredetermined positional relationship, subsequently the lead-out area.16. The device according to claim 14, characterized in that a pluralityof most significant bits in the special codes contain bit combinationswhich do not occur in the address codes.
 17. An optical record carriercomprising: a preformed track including auxiliary signal comprising asequence of codes, the sequence of codes comprising a sequence ofaddress codes and a plurality of special codes, the sequence of codesspecifying addresses of track portions in which the sequence of addresscodes are recorded, and the plurality of special codes specifyingcontrol data for controlling a recording of the optical record carrier,wherein the preformed track consecutively from an inner part of theoptical record carrier comprises: program calibration area reserved forrecorder calibrating purposes; a program memory area for temporarilystoring recorded user content data; a lead-in area for storingdefinitive recorded user content data; a program area for recording userdata; a lead-out area for indicating end of the program area; whereinsaid special codes are recorded in at least one of the lead-in area andthe lead-out area; and an extended area preceding the programcalibration area containing special codes representing additionalcontrol information that are capable of controlling at least one ofplaying and recording of the optical record carrier by a device; whereinthe special codes contain bit combinations which do not occur in theaddress codes and are indicative of commands for controlling the device.18. The optical record carrier of claim 17, wherein the extended areacomprises an extended information area comprising the additional controlinformation, and a buffer area located between the extended informationarea and the program calibration area containing only address codes. 19.The optical record carrier of claim 18, wherein the address codes arerepresented by an absolute playback time relative to a start of thelead-in area, and wherein the buffer area covers a range of absoluteplayback time.
 20. The optical record carrier of claim 18, wherein theaddress codes are represented by an absolute playback time relative to astart of the lead-in area, and wherein the extended information areaprecedes the start of the lead-in area by a predetermined amount of timethat controls displacement of the device.
 21. The optical record carrierof claim 17, wherein a plurality of most significant bits in the specialcodes contain bit combinations which do not occur in the address codes.22. A device for at least one of recording to and playback of an opticalrecord carrier comprising: a reader configured to read informationrecorded on the optical record carrier including reading an auxiliarysignal recorded on the record carrier and extracting special codes andaddress codes from the auxiliary signal; a recorder configured to recordon the optical record carrier in accordance with a recording process;and a controller configured to control the recording process, todetermine a predetermined positional relationship of a periodic patternof address codes and special codes, and to read an extended area on theoptical record carrier upon detecting the predetermined positionalrelationship; wherein the extended area precedes a program calibrationarea containing the special codes representing additional controlinformation that are capable of controlling at least one of playing andrecording of the optical record carrier by the device; and wherein thespecial codes contain bit combinations which do not occur in the addresscodes and are indicative of commands for controlling the device.
 23. Thedevice of claim 22, wherein the extended area comprises an extendedinformation area comprising the additional control information, and abuffer area located between the extended information area and theprogram calibration area containing only address codes.
 24. The deviceof claim 23, wherein the address codes are represented by an absoluteplayback time relative to a start of the lead-in area, and wherein thebuffer area covers a range of absolute playback time.
 25. The device ofclaim 23, wherein the address codes are represented by an absoluteplayback time relative to a start of the lead-in area, and wherein theextended information area precedes the start of the lead-in area by apredetermined amount of time that controls displacement of the device.26. The device of claim 22, wherein a plurality of most significant bitsin the special codes contain bit combinations which do not occur in theaddress codes.